Interface means between a network switch and a CTI server means and apparatus for providing a service to a customer including such an interface means

ABSTRACT

A method for providing a telephony service, the method including coupling an interface device directly between a network switch of a public intelligent network and a computer telephony integration server, the network switch being coupled to a service switching function device having service switching functionality; at the interface device, handling call handling messages between the service switching function device and the computer telephony integration server.

BACKGROUND OF THE INVENTION

This is a Continuation Application of application Ser. No. 10/895,316filed Jul. 21, 2004, which is a Continuation Application of U.S.application Ser. No. 09/346,930 filed Jul. 2, 1999, now U.S. Pat. No.6,842,514. The entire disclosures of prior application Ser. Nos.10/895,316 and 09/346,930 are considered part of the disclosure of thisContinuation Application and are hereby incorporated by reference.

The present invention relates to an interface means between a networkswitch and a Computer Telephony Integration, hereafter abbreviated withCTI, server means and to a method and an apparatus for providing aservice to at least one customer.

Such an apparatus, wherein a network switch as well as a CTI servermeans are coupled via a particular interface, is already known in theart, e.g. from the PCT application WO 98/01987, “Method and apparatusfor implementing a network call center”. Therein a network provider callcenter is described, offering automated call distribution services tocustomers outside it. This network provider call center includes anetwork switch and a computer-telephony integration, abbreviated as CTI,system. This CTI system includes a CTI server, a stat-server and arouting server. The latter two devices are needed for offering theautomated call distribution service of the prior art system, and as suchcorrespond to the executable means for executing the service. The CTIserver, as is described on page 8 of the prior art document, therebyacts as a bridge between the network switch on one hand, and anapplication programming interface to the executable means comprising theprior art stat-server and routing server on the other hand.

Within the prior art system, the network switch is directly coupled tothe CTI-server, via a CTI link of this network switch, as is stated inline 15 of page 8 of the prior art document. The interface means of theprior art system thus consists of such a specific CTI-link. Such aCTI-link may for instance consist of a standardised CSTA interface,whereby CSTA is the abbreviation of Computer SupportedTelecommunications Applications. At the time of the invention, however,most of these public switching network switches do not contain such aCTI link, and consequently need to be especially equipped with this.Furthermore, as is explicitly mentioned in lines 12 to 14 of page 8 ofthe prior art document, in case a network operator who is possessingvarious types of such network switches manufactured by differentcompanies, wants to offer call center services throughout its network,different versions of such CTI servers have to be implemented andinstalled, in order to match with the variety of switches made by thedifferent manufacturers. Together with the fact that these differentversions of the CTI server can only interface with the various networkswitches on the condition that these network switches have such aCTI-link, the prior art solution is very complicated and expensive forpublic switching network operators, since each network switch has to bespecially equipped with a CTI-link and per type of switch a dedicatedCTI server is to be used.

SUMMARY OF THE INVENTION

An object of the present invention is therefore to provide an interfaceand an apparatus of the above known type, but which solves the currentproblem of switch and CTI server incompatibility.

According to the invention, this object is achieved due to the fact thatsaid interface means is further adapted as is explained in thecharacteristic part of the first claim and that said apparatus furtherincludes such an interface means.

In this way, the interface means, adapted to interface now between aservice switching function device within the public network switch onone hand, and the CTI server on the other hand, thereby acts as auniversal bridge between these two domains. Since both the serviceswitching function device in the public network domain and the CTIfunction in the CTI domain have a standardised interface, such as theCS1 or CS-2 interface for the service switching function in the publicnetwork domain and for instance the CSTA interface for the CTI domainrespectively, an interface means which is adapted to communicate withand to convert from one standardised interface to the other, allows anynetwork switch supporting such public network standard to be coupled toany CTI-server supporting such CTI standard. This solution therebyprovides a universal platform for accessing services as these areincited from the CTI server, thus providing an apparatus in which anytype of network switch with a standardised public switching interfacemay be coupled to any type of CTI server means with a standardised CTIinterface.

In this way the call handling function at the CTI side is completelyperformed by the CTI call handling device of the interface means. ThisCTI call handling functionality is thereby removed from the CTI serverto the interface means, again keeping the CTI server simple and cheap.

Thereby, upon executing a particular call service scenario, a returningCTI call handling message is generated.

Yet another characteristic feature of the present invention is describedin claim 4.

Similarly, also a service request control message is generated fortransmission towards the network switch side, upon execution of aspecific CTI call service scenario. This specific CTI service scenariothereby may be the same or may be different from the one for which areturning CTI call handling message is generated.

Thereby public switching network call handling messages, such as forinstance standardised CS2 Intelligent Network protocol call handlingmessages, are received within a mapping device, incorporated within theinterface means. The mapping device is thereby adapted to perform publicswitch call handling. The mapping device thereby acts as a servicecontrol function of the service switching function of the public networkswitch. Indeed, due to the public switching call handling functionalityincorporated within the mapping device, the call handling performedwithin the switch can be reduced to a basic level, whereas within themapping device call handling can be performed at a higher level ofabstraction, related to the intelligent network service control functionapproach. This creates an enormous advantage since with thisarchitecture, services, such as automated call distribution services,can now be provided as a service of an intelligent network environment.This presents advantages of routing control, network wide coverage, andcharging control.

Thereby, returning public switching call handling messages fortransmission towards the network side, as well as control messages fortransmission towards the CTI side, are generated by the mapping device.

In this way CTI call handling scenarios are performed on a particularcall, of which the incoming call handling message originated from thepublic network switching domain. This action may be followed by thegeneration of at least one other CTI call handling message for deliveryto the CTI domain. This latter CTI message can thus be considered as acorresponding message, in the CTI domain, of the original incomingpublic switching call handling message.

As was the case when a CTI call handling scenario was performed on acall handling message from the CTI domain, also in this case a servicerequest control message is generated for back transmission towards thepublic switching network side.

Thereby the mapping device is adapted to perform public switching callservice scenario's on a specific call associated to a message providedby the CTI domain. Thereby other public switching call handling messagesare generated, these thereby to be considered as corresponding to theoriginal call handling message from the CTI domain. Other controlmessages are generated for retransmission back to the CTI call handlingdevice.

In this way, both the CTI call handling device as well as resp. themapping device determine the actual value of the CTI, resp. publicswitching, call attributes such as the call state, calling number andcalled number, of the call associated to their received input message,and update at least one value of these call attributes upon performing aCTI, resp. a public switching call service scenario.

In the descriptive part of this document embodiments of a CTI callhandling device and of a mapping device, adapted to determine theseactual and updated call attributes, are extensively described.

Thereby the CTI call handling device includes a first plurality of CTIcall service scenario devices, each adapted to perform a distinct CTIcall service scenario on a call associated to an incoming CTI callhandling message. The decision about which incoming call handlingmessage is forwarded to which CTI call service scenario device, isperformed by a first selection means, also incorporated within the CTIcall handling device, and is based upon at least one value of the callattributes of the call associated to this incoming call handlingmessage.

Similar to the CTI call handling device, the mapping device alsoincludes a second plurality of public switching call service scenariodevices, each adapted to perform a distinct public switching callservice scenario on a call associated to an incoming public switchingcall handling message. Again a second selection means is adapted todecide which incoming public switching call handling message is to beforwarded to which public switching call service scenario device, thisdecision also based upon at least one value of the call attributes ofthe call associated to this incoming public switching call handlingmessage.

Thereby, also for the messages received from the mapping device, such asfor instance the above described control messages, a selection isperformed within the CTI call handling device, by means of a thirdselection means which decides which mapping device message will beforwarded to an associated CTI call service scenario device of a thirdplurality. These CTI call service scenario devices of the thirdplurality are performing CTI call service scenario's which aresubstantially different from those performed by the CTI call servicescenario devices of the first plurality. This is because CTI callhandling protocols itself are asymmetrical.

Similarly, the decision concerning which CTI call service scenario isselected is performed by the third selection means, based on at leastone value of the CTI call attributes of the call associated to theincoming mapping device message.

Similar to the CTI call handling device, the mapping device alsoincludes a fourth selection means adapted to discriminate amongstincoming messages received from the CTI call handling device, such asthe above mentioned service request control signals. These CTI callhandling device messages are as well forwarded to a public switchingcall service scenario device of a fourth plurality, based on at leastone value of the public switching call attributes of the call associatedto the incoming CTI call handling device message.

The public switching call service scenario's performed by similar nameddevices of the fourth plurality are different from those performed bythe devices of the second plurality. The reason behind this differenceis also related to the asymmetry of the public switching call handlingprotocol itself.

The interface means may as well be part of an apparatus.

In this way the interface means interfaces with several serviceswitching function devices which may be residing on different or on thesame network switches. This has the advantage that only one application,being the CTI server application as provided by the CTI server meansitself, or an application from an executable means coupled via theapplication programming interface to the CTI server means, can controlseveral service switching functions at the same time. This was until nownot possible with the prior art architecture.

The interface means may thereby also interface with several CTI servers.Since each of these CTI server may be coupled to an applicationprogramming interface from which several applications or services may beinvoked, this architecture thereby increases the amount of availableservices to be offered by for instance a network operator.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects and features of the invention will becomemore apparent and the invention itself will be best understood byreferring to the following description of an embodiment taken inconjunction with the accompanying drawings wherein:

FIG. 1 schematically represents an apparatus A including an interfacemeans IM according to the invention,

FIG. 2 schematically depicts parts of the apparatus of FIG. 1, andillustrates how incoming CTI call handling messages are treated.

FIG. 3 is a continuation of the drawing of FIG. 2, depicting furtherparts of the CTI call handling device of FIG. 2

FIG. 4 schematically depicts parts of the apparatus of FIG. 1. Andillustrates how incoming public switching call handling messages, aretreated.

FIG. 5 is a continuation of the drawing of FIG. 4, depicting furtherparts of the mapping device of FIG. 4.

FIG. 6 schematically shows an embodiment of an interface means,interfacing with several service switching devices and with several CTIservers.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows an embodiment of an apparatus A for providing services suchas automated call distribution services or other operator assistedservices, to a customer C. The apparatus basically consists of a networkswitch SSP, an interface means IM, a CTI server means CTS, anapplication programming interface API and executable means for executingthe service. In FIG. 1 several executable means are depicted, anddenoted with EM1 to EM5, showing that several services, provided bythese respective executable means, are provided. Both CTI server CTS aswell as the executable means are installed on one or several computers,which are linked to each other. The interface means IM consists as wellof a computer program which is installed on the same or on anothercomputer, coupled in between the network switch SSP and the computer onwhich the CTI server CTS is installed. The applications performed by thedifferent executable means comprise the mentioned services such as theautomated call distribution service, wake-up service, billing service,statistics service and operator assisted services such as directoryassistance and call completion.

The customer C of FIG. 1 is possessing a telephony apparatus T which isconnected via a telephone link TL to the network switch SSP, and moreparticularly to the service switching function device SSF within thenetwork switch. The customer as well includes a computer CO having itsown application programming interface, in FIG. 1 denoted by CAPI. Thelatter is coupled via a computer link CL to the CTI server CTS. Thetelephony apparatus T of the customer is coupled to the computer CO ofthe customer by means of an internal link, denoted L. Such a customermay for instance consist of a single agent possessing merely a telephoneterminal coupled to a stand-alone computer, but it may as well consistof for instance a large call center, including a private branch exchangePBX with a lot of internal telephone terminals coupled to it, coupled toa local area computer network of several interconnected computers.

CTI servers generally operate in the computer telephony integration,abbreviated with CTI, domain, whereas network switches operate in thepublic switching domain. Both domains are at the moment of the inventionrather incompatible. CTI protocols include a minimum of call controlcommands such as make a call, clear a call etc. The majority of theseCTI protocols have been defined by private switch suppliers to supportaccess to and control of their own products. However a small number ofstandardised protocols have been defined of which CSTA, being theabbreviation of Computer Supported Telecommunications Applications, andsupported by the European Computer Manufacturers Association,abbreviated by ECMA, is one of the most important.

Private branch exchanges, abbreviated with PBX, coupled to hostcomputers on which CTI applications are running, in general are equippedwith a so-called CTI-link, supporting one of the aforementioned CTIprotocols such as the CSTA protocol. Public switches however are ingeneral not equipped with such a link. When addressing services in thepublic switching domain, an intelligent network approach is used.Therein public network switches may act as a service switching point,which is further coupled to a service control point from which theservices are invoked. Within the intelligent network environment howeverother protocols compared to CTI protocols apply. One of the standardisedintelligent network protocols consists of Capability Set, abbreviatedwith CS, versions 1 and 2. However a different call handling model,compared to the one applicable in CTI protocols, is used within theintelligent network environment.

The subject invention envisages to offer services, generally associatedto the CTI domain, as services within an intelligent networkconfiguration. To this purpose an interface means is developed, which isadapted to communicate between a service switching function device SSF,running on the network switch SSP, and the CTI server means CTS

In one embodiment of the interface means, the interface means iscommunication with a CSTA protocol at the CTI server means, and with aCS-2 protocol of the network switching function SSF.

However other versions of such interface means can be provided forinterfacing with other public network service switching functionprotocols as well as with other CTI protocols, their basic architectureall corresponding to the one described in the following paragraphs.

Such an interface means IM, as can be observed from FIGS. 2 and 4, ingeneral consists of two main building blocks: a CTI call handlingdevice, denoted with CTICH, and a mapping device, denoted with MD.Within these respective figures is depicted how CTI call handlingmessages, respectively public switching call handling messages, aretreated within the interface means. The circles including differentnumbers thereby refer to the sequence of events, or generated signals,in function of the time. The circle including number 1 thus refers tothe first event, the circle including number 2 then refers to the nextevent and so on.

As depicted in FIG. 2, call handling messages provided by the CTI servermeans CTS and originating from the CTI domain, are first received withina first selection means denoted SM1 and included within the CTI callhandling device CTICH. In general the CTI call handling device isadapted to receive from the CTI server, CTI call handling messages suchas the message CTICHIN, and to perform on respective calls associatedwith these respective call handling messages, call service scenario's asthese are defined in the CTI domain. Thereby returning CTI call handlingmessages, such as CTICHOUT2 of FIG. 2, may be generated for transmissionback to the CTI interface of the interface means. Besides generatingappropriate CTI returning call handling message to the CTI domain, theCTI call handling device may as well generate service request controlmessages such as for instance SRCM1 of FIG. 2, for transmission towardsthe mapping device MD.

In the embodiment depicted in FIG. 2 I such CTI call service scenariosare available within the CTI call handling device CTICH for treatingcalls associated to CTI call handling messages originating from the CTIdomain such as CTICHIN. The selection upon which of these I call servicescenario's is to be executed, is performed by the first selection meansdenoted SM1. The latter device is adapted to decide, based oninformation extracted from the incoming call handling message, and basedon information received from two memory devices incorporated withinCTICH, which of the I CTI call service scenario's is to be performed ona specific call associated to that incoming call handling message. SM1is therefore coupled, via I distinct connections of which only two areshown in order to not overload the drawings, to each of these I CTI callscenario devices denoted CSCEN1 to CSCENI. In FIG. 2 SM1 has selecteddevice CSCEN1, for performing a same named CTI call service scenario, onthe call associated to CTICHIN. Accordingly CTICHIN is provided towardsCSCEN1, this representing a second event. At the same time that CTICHINis delivered to CSCEN1, SM1 also generates another message, denoted C2,towards the a second CTI memory device, denoted M2CTI on FIG. 3 which isan extension of FIG. 2. Since for explaining the succession of callhandling actions within the interface means these messages transmittedand received to these memory devices are in a first level not mandatory,their meaning and relevance to the invention will be described in afurther paragraph of this document.

CTICHIN is received by CSCEN1, the latter device performing a same namedcall service scenario on the associated call. For the case depicted inFIG. 2, upon performing this CTI call service scenario, a returning CTIcall handling message, denoted CTICHOUT2 is generated and transmittedback to the CTI server means CTS. At the same time a service requestcontrol message SCRM1 is also generated for transmission towards themapping device MD. It has to be remarked however that not all CTI callservice scenario's will result in the generation of such signals.Depending on which scenario is performed on which input message, eitherno output signals are generated, or only those of the returning CTItype, or only those of the service request control type, or anycombination of both. Also more than one output signal of either type maybe generated, any numerically combination of both type of output signalsthus being the result. How many signals, and of which type, aregenerated, depends on the call service protocol used at the CTI side, onthe scenario itself and on the input call handling message referring toa specific call.

Remark that, upon performing a call service scenario on an inputmessage, a CTI call handling scenario device, for instance CSCSN1, isadapted to generate another type of message, such as C3 of FIG. 2, fortransmission towards the second CTI memory device M2CTI.

The thus generated service request control message, SCRM1, istransmitted towards the mapping device MD. The latter includes a fourthselection means, denoted SM4 on FIG. 2, which is adapted to receive fromthe CTI call handling device CTICH a succession of such service requestcontrol messages. As was the case for the first selection means SM1, SM4is adapted to forward an incoming message to one of a fourth pluralityof public switching call service scenario devices, denoted SCENn+1 toSCENn+m. Which public switching call service scenario is selected forwhich input message, again depends on the input message itself, as wellas on information transmitted from a first and second memory publicswitching device, M1PS and M2PS, included within the mapping device MD.Again, these memory devices as well as the signals transmitted andreceived by them will be discussed in a later paragraph of thisdocument.

In the example depicted in FIG. 2, SM4 forwards SCRM1 to publicswitching service scenario device SCENn+m. The latter device is adaptedto perform a same named public switching call service scenario on a callassociated to input signal SCRM1. For the example depicted in FIG. 2this results in a public switching call handling message PSCHOUT3 beinggenerated, which is further transmitted to the service switchingfunction device within the network switch SSP. At the same time acontrol signal, denoted CMn+m, is also generated and transmitted back tothe CTI call handling device CTICH. The same remarks as for the CTI callservice scenario devices are also valid for the mapping device: uponperforming a public switching call service scenario, either no outputsignals may be generated, or any combination of a certain amount ofpublic switching call handling messages and another amount of returningcontrol messages towards the CTI side. The resulting output signals arefunction of the specific call service scenario performed, the inputsignals, the calls associated to them, and the information received fromthe two public switching memory devices as will be explained in afurther paragraph.

Again, each time an action is performed, either by the fourth selectionmeans SM4, or by the specific public switching call service scenariodevices, a control signal is transmitted towards the second publicswitching memory device M2PS. These respective control signals aredenoted C4 and C5, transmitted by the respective devices SM4 and SCENn+mupon having performed an action. Their importance will be discussed inthe paragraph where the function of the respective memories will beexplained.

As further depicted in FIG. 2, control message CMn+m transmitted bySCENn+m to the CTI side, is received within the CTI call handling deviceCTICH within a third selection means SM3. As for the already describedother two selection means, SM3 is adapted to receive a succession ofincoming messages, in this case consisting of control messages deliveredby public switching call service scenario devices of the mapping deviceMD. SM3 is adapted to forward each of them to one of a third pluralityof CTI call service scenario devices, denoted CSCENI+1 to CSCENI+k.Remark however that the CTI call service scenario devices that arecoupled to SM3 are distinct from those coupled to SM1. Thus other callservice scenario's are performed on calls associated to control messagesreceived from the mapping device, compared to those on calls associatedto incoming CTI call handling messages

In the example depicted by FIG. 2, control message CMn+m is forwardedvia SM3 to CTI call service scenario device CSCENI+1. The latter devicethen performs on the call associated to CMn+m a CTI call servicescenario also denoted CSCENI+1. Also in this case the result beinganother returning CTI call handling message CTICHOUT2′ as well asanother service request control message SCRPMI+1.

Again, messages are generated by SM3 and CSCENI+1 for transmission tothe second CTI memory device M2CTI. These messages are respectivelydenoted C6 and C7.

The service request control message SCRMI+1, generated by CSCENI+1 isnow transmitted back towards the fourth selection means SM4. The latterdevice now selects SCENn+1 to perform a same named public switching callservice scenario on the call associated to SCRMI+1. In this case theresult will only be another public switching call handling messagePSCHOUT3′, which will be delivered to the network switch. No furthermessage is generated for transmission towards the CTI side. Only twoextra messages, C8 and C9 are additionally generated by SM4, resp.SCENn+1, for transmission towards M2CTI. The call handling is therebyfinished for the example depicted in FIG. 2., which started with anincoming CTI call handling message, and which resulted in two returningCTI call handling messages and two public switching call handlingmessages being generated.

FIG. 4 gives an example of the actions performed by the interface means,whereby the input signal is now delivered by the service switchingfunction device SSF within the network switch SSP.

This input signal is denoted PSCHIN, being a public switching callhandling message. This message is received by the mapping device MD, andmore particularly by a second selection means SM2 included therein.

SM2 then forwards the incoming public switching call handling messagePSCHIN to one of a second plurality of public switching call servicescenario devices SCEN1 to SCENn. Remark that also these public switchingcall service scenario devices included within this second plurality aredifferent from those included in the fourth plurality, which werereceiving service request control messages from the CTI call handlingdevice CTICH.

For the example depicted in FIG. 4 SM2 is adapted to forward PSCHIN topublic switching service scenario device SCEN1. The latter is adapted toperform a same named public switching call service scenario on the callassociated with PSCHIN, and to thereby generate a returning publicswitching call handling message PSCHOUT1, as well as a control messageCM1 for delivery to the CTI call handling device.

The same remark concerning the generation of output signals as well assignals towards the memory devices, is valid for any public switchingcall service scenario device included in the second plurality, as forthe public switching call service scenario devices included in the otheralready described pluralities. Thus two more signals are generated: C2′by SM2 and C3′ by SCEN1, these signals being transmitted towards thesecond public switching memory device M2PS.

CM1 is then transmitted towards the CTI call handling device CTICH,where it is received by the third selection means SM3, as was the casefor the signal CMn+m of FIG. 2. From now on more or less the sameprocedure as was described in FIG. 2 is followed: SM3 forwards thecontrol message CM1 to one of the CTI call service scenario devices ofthe third plurality, which then performs a CTI call service scenario onthe call associated to the control message, and eventually generatesoutput signals to the CTI and/or to the public network side. In FIG. 4CM1 is forwarded to CSCENI+1. The latter device, upon having performed asame named CTI call service scenario, generates a CTI call handlingmessage CTICHOUT1 for delivery to the CTI server means CTS, and aservice request control message SCRMI+1 which is accordingly transmittedto the fourth selection means SM4 of the mapping device MD. SM4 selectsSCENn+1 to be the one to be performed on the call associated to SCRMI+1.Upon performing this public switching call service scenario, anotherreturning public switching call handling message PSCHOUT2 is generated,as well as another control message CMn+1. The latter is received by SM3,which now selects CSCENI+k to be the CTI service scenario to beperformed on the call associated with CMn+1. Thereby a final CTI callhandling message CTICHOUT1′ is generated for transmission to the CTIserver means CTS.

As already mentioned, each time one of the described devicesincorporated within the mapping device and the CTI call handling device,has performed an action, a control message towards either a secondpublic switching memory or a second CTI memory device was transmitted.The second CTI memory device, denoted M2CTI, thereby received signalsdenoted C4′, C5′, C8′ and C9′, transmitted from respective devices SM3,CSCENI+1, SM3 and CSCENI+k for the case depicted in FIG. 4. The secondpublic switching memory device M2PS, depicted on FIG. 5 which is anextension of FIG. 4, thereby received C2′, C3′, C6′ and C7′ fromrespective devices SM2, SCEN1, SM4 and SCENn+1. For the case depicted inFIG. 2, M2PS received signals denoted C4, C5, C8 and C9 from respectivedevices SM4, SCENn+m, SM4 and SCENn+1 and M2CTI, depicted in FIG. 3which is an extension of FIG. 2, received signals denoted C2, C3, C6 andC7 from respective devices SM1, CSCEN1, SM3 and CSCENI+1.

Besides the second CTI and public switching memory devices, M2CTI andM2PS, the CTI call handling device, respectively mapping device, alsoinclude a first CTI memory device M1CTI, and a first public switchingmemory device M1PS respectively.

The first public switching memory device M1PS stores data concerning thepublic switching call model as well as concerning the public switchingsubscriber profile. This data is stored within M1PS duringinitialisation of the interface means and will not change during theoperation of the interface means or of the apparatus. Similarly thefirst CTI memory device M1CTI stores information regarding the CTI callmodel and CTI subscriber profile, again provided to this memory deviceduring initialisation of the interface means.

The second public switching memory device M2PS on the other hand storesdata concerning the public switching call attributes of each treatedcall, such as the calling number, the called number, and the states inwhich this specific call may reside, according to a specific publicswitching call model. Since this data is continuously changing,especially during operation of the interface means, the second publicswitching memory device M2PS continuously is to be updated with thelatest value of the call attributes. This is done by means of thesignals transmitted by each of the public switching call scenariodevices or selection means, included within the mapping device, uponhaving performed a particular action on a specific call. Indeed, in oneembodiment of the interface means the mentioned devices are adapted to,upon receiving an incoming message, either a public switching callhandling message or a service request control message from by the CTIcall handling device, to extract from this incoming message, informationrelated to the actual value of the public switching call attributes ofthe call associated to this incoming message, to determine therefrom atleast one updated value of the call attributes of this call, and totransmit this information back to the second public switching memorydevice. Within the second selection means, the calculation of theupdated call attributes is thereby based upon the actual value of thecall attributes extracted from the incoming message, but also based onpublic switching call model and subscriber profile data delivered by thefirst public switching memory means, and based on public switching callattribute information, stored within and delivered by the second publicswitching memory device M2PS. In FIGS. 4 and 5, the signal including thepublic switching call model and subscriber profile data, transmittedfrom the first public switching memory device M1PS to both SM2 and SM4is denoted M1PS′. The signal containing the latest value of at least oneof the public switching call attributes, provided by M2PS to SM2 isdenoted CAIPSSM2′. In some embodiments, both information signals areonly delivered to SM2, upon request of SM2. SM2 thus only asks M1PS orM2PS for the information, if required, in order to enable SM2 tocalculate the updated call attributes of the call associated to theincoming messages. At the same time, all this requested and extractedinformation also enables SM2 to accordingly select the appropriatepublic switching call handling scenario to be performed on an incomingpublic switching call handling message, in accordance to a particularpublic switching call handling model such as for instance the CS2 model.Once the at least one updated value of the call attributes are thendetermined by SM2, this second selection means provides this informationback to M2PS by means of signal C2 of FIG. 4, M2PS accordingly storingthe thus received updated call attributes.

The public switching call scenario devices are also adapted to firstcalculate the call attributes of the call associated to an incomingmessage, from information extracted from this message. In the embodimentdepicted in FIG. 4, no information is however provided from the memorydevices towards the call service scenario devices. To yet allow thelatter devices to determine the correct updated value of the callattributes, in this embodiment the second selection device furtherprovides the selected call service scenario device with this necessaryinformation, which SM2 calculated earlier. This is not shown on thefigures in order to not overload them. Anyway, upon having performed apublic switching call service scenario, each of these public switchingcall service scenario devices also provides M2PS with informationconcerning the updated value of the associated call attributes. Thisinformation is thus contained within for instance signal C3′ on FIG. 4.

The fourth selection means SM4, which is receiving a incoming CTI callhandling device message, also extracts from this message call attributeinformation. Since this message is provided by the CTI call handlingmeans, in this embodiment, the extracted call attributes are however CTIcall attributes. SM4 thus is to be additionally adapted to perform aconversion between the extracted CTI call attributes and correspondingpublic switching call attributes. After performing this conversion, thesame procedure as for SM2 is followed: at least one updated value of thepublic switching call attributes is determined from the values extractedfrom the incoming message, and from information provided, eventually onrequest, by both memory devices M1PS and M2PS. This information isprovided, possibly on request from SM4, from these respective memorydevices by means of respective information signals MIPS′ and CAIPSSM4′.Similarly, upon calculating the at least one updated call attributevalues, the latter are provided by to M2PS by means of a signal such asfor instance C6′ in FIG. 4. Similar to SM2, the fourth selection meansSM4, also uses the provided and extracted information to properly selectone public switching call service scenario out of the fourth plurality.And for the embodiment depicted in FIG. 4, the fourth selection devicealso provides a selected public switching call handling scenario devicewith further information to allow the latter to properly determine theupdated call attributes (this is however not shown on FIG. 4). Uponhaving determined these updated call attributes, they are provided tothe second public switching memory device by means of anotherinformation signal such as for instance C7′ of FIG. 4, transmitted fromSCENn+1 to M2PS.

A similar procedure is taking place in the CTI call handling deviceCTICH. Therein also the second CTI memory device M2CTI is to becontinuously updated in order to store the latest values of the CTI callattributes of each treated call. To this purpose, the differentselection means SM1 and SM3 and CTI call service scenario devicesincluded within the first and second plurality of CTI call servicescenario devices, are each providing this second CTI memory device withthe updated value of the call attributes they determined, uponperforming their specific task on an incoming message. The selectionmeans SM1 and SM3 thereby calculate at least one updated value of theCTI call attributes of the call associated to their input message, byfirst extracting from this incoming message the actual CTI callattributes of the associated call. For SM1, receiving a CTI callhandling message, this can be performed in a rather straightforward way,by analysing the incoming CTI message. For SM3, receiving a controlmessage from the public switching domain, thus containing references topublic switching call attributes, these are first extracted from thecontrol message, after which step SM3 has to perform a conversion fromthese extracted public switching call attributes in the public switchingdomain, to corresponding CTI call attributes in the CTI domain.

The updated values of the CTI call attributes are then furthercalculated based on information received from both CTI memory devices,which may be, although not necessary, specifically requested by therespective selection means. The CTI call model and subscriber profiledata is provided by the first CTI memory device M1CTI towards bothselection means, by means of the signal denoted M1CTI in FIG. 2 and FIG.3. The latest value of the requested CTI call attributes is provided byM2CTI to SM1 by means of information signal CAICTISM1, and to SM3 bymeans of information signal CAICTISM3.

Both selection devices SM1 and SM3 not only use the thus providedinformation for calculating the updated call attributes, but also forselecting one of the CTI call service scenario devices of the first,respectively third plurality.

Upon having calculated the at least one updated value of the CTI callattributes associated to their incoming messages, SM1 and SM3 providethis information back to M2CTI by means of for instance respectivesignals denoted C2 and C6 of FIGS. 2 and 3.

Also the CTI call service scenario devices are calculating at least oneupdated value of the CTI call attributes associated to incomingmessages. In the embodiment depicted in FIGS. 2 and 4, no information isprovided from both CTI memory devices to the CTI call service scenariodevices, therefore the selection means coupled to the respective CTIcall service scenario devices, are providing these with this necessaryinformation (not shown in these figures).

However other embodiments of the interface means exist where thisinformation is provided directly from the memory means to the servicescenario devices. Since different implementations for updating the callstates by the selection means and call service scenario means arecommonly known to a person skilled in the art, these will not be furtherdiscussed within this document.

Upon having calculated the at least one updated value of the callattributes associated to their input messages, the CTI call servicescenario devices are communicating this information to the second CTImemory means. In FIG. 2 this is depicted by the signals C3 and C7,respectively generated and transmitted by CSCEN1 and CSCENn+1. For thecase depicted in FIG. 4, CSCENI+1 and CSCENI+k are generating andtransmitting signals C5′ and C9′; whereas SM3 has generated andtransmitted C4′ and C8′ towards M2CTI.

Until now the apparatus has been described for the case one interfacemeans is coupled between one network switch and one CTI server. In amore general case however, such as depicted in FIG. 6, an interfacemeans IM′ is adapted to interface with more than one service switchingdevice, and with more than one CTI server. In FIG. 6 these differentservice switching devices are denoted SSF, SSF1, SSF2 and SSF3, and thedifferent CTI servers are denoted CTS, CTS1, and CTS2. These differentservice switching devices may be incorporated in the same networkswitch, or distributed over several network switches, such as shown inthe embodiment of FIG. 6, where service switching devices SSF1 and SSF2are part of the same network switch SSP1, SSF is part of network switchSSP, and SSF3 is part of SSP2. This presents the advantage of increasedperformance with respect to offered applications, since each CTI serveris in general coupled to an application programming interface (not shownon FIG. 6), and increased performance with respect to network-widecoverage.

For implementing such an interface means IM′, several options arepossible. Within a first realisation, each service switching functiondevice is coupled to a corresponding mapping device, and each CTI servermeans is coupled to a corresponding CTI call handling device. Thecommunication signals between the respective mapping devices and CTIcall handling devices thereby reflect which service switching functiondevice is to be coupled to which CTI server means, at both sides of theinterface means. Since however several CTI servers have to be able toshare the same CTI objects such as the call states etc., within thisfirst realisation the different memories of these different CTI servermeans have to be shared. Within a second realisation, each serviceswitching function device is again coupled to a corresponding mappingdevice, but there is only one big CTI call handling device interfacingwith all CTI server means.

An additional remark is related to processing power considerations. Aninterface means, such as IM and IM′ previously described, in generalconsists of a computer program, running on a computer, processor orserver. In order to increase performance such as speed, additionalprocessing power can be added. A consequence of this is the distributionof the operation of this computer program constituting the interfacemeans, over different processors or servers. Thereby, reliability isalso increased. Furthermore, servers can be physically placed close tothe server on which the applications are running, or may be the same,thereby reducing possible delays.

While the principles of the invention have been described above inconnection with specific apparatus, it is to be clearly understood thatthis description is made only by way of example and not as a limitationon the scope of the invention, as defined in the appended claims.

1. A method for providing a telephony service, the method comprising:coupling an interface device directly between a network switch of apublic intelligent network and a computer telephony integration server,the network switch being coupled to a service switching function devicehaving service switching functionality; at the interface device,handling call handling messages between the service switching functiondevice and the computer telephony integration server.
 2. The methodaccording to claim 1, wherein the handling of the call handling messagescomprises: receiving at a computer telephony integration call handlingdevice of the interface device a call handling message from the computertelephony integration server; and performing at the computer telephonyintegration call handling device an operation corresponding to the callhandling message at least one computer telephony integration callservice scenario.
 3. The method according to claim 2, further comprisinggenerating at the computer telephony integration call handling device areturning computer telephony integration call handling message fordelivery to the computer telephony integration server upon performingthe at least one computer telephony integration call service scenario.4. The method according to claim 2, further comprising generating at thecomputer telephony integration call handling device a service requestcontrol message for delivery towards the service switching functiondevice upon performing the at least one computer telephony integrationcall service scenario.
 5. The method of claim 2, further comprising:receiving at a mapping device of the interface device a public switchingcall handling message from the service switching function device; andperforming at mapping device an operation corresponding to the publicswitching call handling message for at least one public switching callservice scenario.
 6. The method according to claim 5, further comprisinggenerating at the mapping device a returning public switching callhandling message for delivery to the service switching function deviceupon performing the at least one public switching call service scenario.7. The method according to claim 5, further comprising generating at themapping device a control message for delivery towards the computertelephony integration server upon performing the at least one publicswitching call service scenario.
 8. The method according to claim 5,further comprising: receiving at the computer telephony integration callhandling device a mapping device message from the mapping device; andperforming at the computer telephony integration call handling device atleast one other computer telephony integration call service scenarioassociated with the mapping device message.
 9. The method according toclaim 8, further comprising generating at the computer telephonyintegration call handling device at least one other returning computertelephony integration call handling message for delivery to the computertelephony integration server upon performing the at least one othercomputer telephony integration call service scenario.
 10. The methodaccording to claim 8, further comprising generating at the computertelephony integration call handling device at least one other servicerequest control message for delivery to the mapping device uponperforming the at least one other computer telephony integration callservice scenario.
 11. The method according to claim 5, furthercomprising: receiving at the mapping device a computer telephonyintegration call handling device message from the computer telephonyintegration call handling device; and performing at the mapping deviceat least one other public switching call service scenario upon aspecific call associated to the computer telephony integration callhandling device message.
 12. The method according to claim 11, furthercomprising generating at the mapping device at least one other returningpublic switching call handling message for delivery towards the serviceswitching device upon performing the at least one other public switchingcall service scenario.
 13. The method according to claim 11, furthercomprising generating at the mapping device at least one other controlmessage for delivery towards the computer telephony integration callhandling device upon performing the at least one other public switchingcall service scenario.
 14. The method according to claim 2, furthercomprising: determining at the computer telephony integration callhandling device the value of the computer telephony integration callattributes of the public switching call handling message upon receivingthe computer telephony integration call handling message, anddetermining at the computer telephony integration call handling deviceat least one updated value of the computer telephony integration callattributes of the public switching call handling message upon performingthe at least one computer telephony integration call service scenario.15. The method according to claim 5, further comprising: determining atthe mapping device the value of the public switching call attributes ofthe call, upon receiving the public switching call handling message; anddetermining at the mapping device at least one updated value of thecomputer telephony integration call attributes of the call, uponperforming the at least one public switching call service scenario. 16.The method according to claim 8, further comprising: determining at thecomputer telephony integration call handling device the value of thecomputer telephony integration call attributes of the particular call,upon receiving the mapping device message; and determining at thecomputer telephony integration call handling device at least one updatevalue of the computer telephony integration call attributes of theparticular call, upon performing the at least one other computertelephony integration call service scenario.
 17. The method according toclaim 11, further comprising: determining at the mapping device thevalue of the public switching call attributes of the specific call, uponreceiving the computer telephony integration call handling devicemessage; and determining at the mapping device at least one updatedvalue of the public switching call attributes of the specific call, uponperforming the at least one other public switching call servicescenario.
 18. The method according to claim 14, further comprising:receiving at the computer telephony integration call handling device asuccession of incoming computer telephony integration call handlingmessages including the computer telephony integration call handlingmessage from the computer telephony integration server; and receiving atthe computer telephony integration call handling device an incomingcomputer telephony integration call handling message of the succession,and forwarding the incoming computer telephony integration call handlingmessage to a computer telephony integration service scenario device of afirst plurality of computer telephony integration call service scenariodevices included within the computer telephony integration call handlingdevice, each of the computer telephony integration call service scenariodevices of the first plurality being adapted to perform a distinctcomputer telephony integration call service scenario, the computertelephony integration call service scenario device of the firstplurality is thereby selected by a first selection means based upon atleast one value of the computer telephony integration call attributes ofthe call associated to the incoming computer telephony integration callhandling message.
 19. The method according to claim 15, furthercomprising receiving at the mapping device a succession of incomingpublic switching call handling messages including the public switchingcall handling message from the service switching function device; andreceiving at the mapping device an incoming public switching callhandling message of the succession, and forwarding the incoming publicswitching call handling message to a public switching service scenariodevice of a second plurality of public switching call service scenariodevices included within the mapping device, each of the public switchingcall service scenario devices of the second plurality being adapted toperform a distinct public switching call service scenario, the publicswitching call service scenario device of the second plurality isthereby selected by a second selection means based upon at least onevalue of the public switching call attributes of the call associated tothe incoming public switching call handling message.
 20. The methodaccording to claim 16, further comprising receiving at the computertelephony integration call handling device a succession of incomingmapping device messages including the mapping device message; andreceiving at the computer telephony integration call handling device anincoming mapping device message of the succession, and forwarding theincoming computer telephony integration call handling message to acomputer telephony integration service scenario device of a thirdplurality of computer telephony integration call service scenariodevices included within the computer telephony integration call handlingdevice, each of the computer telephony integration call service scenariodevices of the third plurality being adapted to perform a distinctcomputer telephony integration call service scenario, the computertelephony integration call service scenario device of the thirdplurality is thereby selected by a third selection means based upon atleast one value of the computer telephony integration call attributes ofthe call associated to the incoming mapping device message.
 21. Themethod according to claim 17, further comprising receiving at themapping device a succession of incoming computer telephony integrationcall handling messages including the computer telephony integration callhandling message; and receiving at the mapping device an incomingcomputer telephony integration call handling message of the succession,and forwarding the incoming computer telephony integration call handlingmessage to a public switching service scenario device of a fourthplurality of a public switching call service scenario devices includedwithin a mapping device, each of the public switching call servicescenario devices of the fourth plurality being adapted to perform adistinct public switching call service scenario, the public switchingcall service scenario device of the fourth plurality is thereby selectedby a fourth selection means based upon at least one value of the publicswitching call attributes of the call associated to the incomingcomputer telephony integration call handling device message.
 22. Themethod according to claim 20, wherein the computer telephony integrationcall service scenarios performed by the computer telephony integrationcall service scenario devices of the plurality are substantiallydifferent from the computer telephony integration call servicescenario's performed by the computer telephony integration call servicescenario devices of the third plurality.
 23. The method according toclaim 21, wherein the public switching call service scenarios performedby the public switching call service scenario devices of the secondplurality are substantially different from the public switching callservice scenario's performed by the public switching call servicescenario devices of the fourth plurality.
 24. The method according toclaim 1, wherein said interface device is adapted to communicate betweena plurality of service switching function devices including the serviceswitching function device, and the computer telephony integrationserver, each of the service switching function devices having a serviceswitching functionality.
 25. The method according to claim 1, whereinthe interface device is adapted to communicate between said serviceswitching function device and a plurality of computer telephonyintegration server, including the computer telephony integration server.